BC is a chord with centre O. A is a point on an arc BC . Prove that: `angleBAC−angleOBC=90^@` , if A is the point on the minor arc

Explanation

`therefore` z=2x

In `triangleOBC`

`angleOBC+angleOCB+angleBOC=180^*`

`y+y+t=180^*`

`t=180^*-2y`

As, `z=360^*-t`

`z=360^*-180^*+2y`

`2x=180^*+2y` (z=2x)

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